Partial support to reimburse travel expenses for invited speakers to the 41st Gordon Research Conference on Cancer is requested. The conference is entitled Cancer and Differentiation and will take place Aug 20-25 at Salve Regina College, Newport, RI The Cancer Conference is the oldest of the Gordon Conferences and is unique in that it deals with broad themes of interest to both basic and clinical researchers. The aim of the 1989 Conference on Cancer is to discuss recent advances on proto-oncogene function, both as normal and tumor genes. Special emphasis will be given to studies of proto-oncogene expression during development and gamete maturation and to the identification of cell lineages and stem cells in normal and neoplastic tissues. The meeting will include 9 plenary sessions, each introduced by a chairman with ample time for discussion. The titles of the sessions are: 1) Oncogenes in human cancers; 2) Oncogenes in carcino- genesis and progression; 3) Protooncogenes and cell differentiation; 4) Protooncogenes and development; 5) Growth factors in development, healing, regeneration and senescence; 6)Tissue interactions in normal and neoplastic growth; 7) Stem cells in normal and neoplastic tissues; 8) Stem cells in liver development and carcinogenesis; 9) Cell lineages and tumor development in the central nervous system. Poster sessions will take place late afternoon throughout the week. We expect that approximately 130 scientists (from universities, research institutes, industry and government) will be selected among the applicants to attend the Conference. Scientists not giving formal presentations will be asked to present their work in poster form. The Gordon Research Conferences on Cancer have played an important role in determining future directions in cancer research and it is expected that given the theme and the quality of the speakers, the 1989 conference will have a similar impact.